In recent years, cameras of the type known as disposable or single-use cameras have grown in popularity. These cameras consist of a roll of film preloaded into a simple, inexpensive camera housing having an exposure window and a film cassette-receiving chamber on one side of the exposure window, and a film-receiving chamber on the other. The film is typically loaded such that the camera is ready for immediate use by a purchaser. Once all of the film in the camera has been exposed, the entire camera may be sent by the user to a film processing company which removes the film from the camera and develops the pictures.
Disposable cameras are available which utilize a variety of film formats, including conventional 35 mm films. A "roll" of such film consists of a length of film prewound in a generally cylindrical housing or film cartridge or cassette. During the assembly of disposable cameras, the free end or tail of the film ordinarily is pulled from the film cartridge and connected to a winding spool, and the winding spool and film cartridge are assembled in the film-receiving chambers on opposite sides of the exposure window in a front portion of the camera housing. A rear housing portion is then assembled to the front housing portion to enclose the film therein. Once the housing has been assembled to prevent light from exposing the film, the winding spool may be rotated to wind the film from the cartridge onto the spool to place the camera in condition for use. As pictures are taken, the film is rewound frame-by-frame from the winding spool back into the film cartridge.
There are problems associated with the use of a winding spool in the disposable cameras described above. Most notably, since the tail of the film is connected to the winding spool, advancing the film after the exposure of a frame causes the winding spool to turn, and this creates a resistance to the film movement. To overcome this resistance, more force is required to operate the film advancement mechanism after frame exposure.
One proposed solution is to use a substantially cylindrical spoolless film-receiving cartridge. The film supply cartridge and film-receiving cartridge are then loaded into the film-receiving chambers on opposite sides of the exposure window in the front portion of the camera housing, and a rear cover is assembled thereto. While this arrangement eliminates the winding spool and thus the resistance it creates to the advancement of the film, the need for a film-receiving cartridge adds weight to the camera and increases its manufacturing cost. Furthermore, since the film is wound from the supply cartridge to the receiving cartridge outside of the camera, this procedure must be performed under darkroom conditions, slowing production and adding to manufacturing costs.
It is also known to use a separate winding tool to which the leading end of the film is attached which is placed into the film-receiving chamber and rotated to unwind the film from the cassette. After winding, the tool is removed and the back of the camera fitted onto the camera body. This technique also requires darkroom conditions, slowing production and increasing costs.
There therefore exists a need for a disposable or single-use camera which not only overcomes the problems associated with the use of a winding spool in these cameras, but allows daylight loading and which does so without increasing the weight of the camera or its manufacturing costs.